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By M. Leroux, S. R. Rao, J. Kim, J. A. Finch

"Continuous in-plant testing of collectorless Cu/Pb bulk flotation on Lyon Lake ore at Matlabi Mines Ltd. Was conducted using a portable circuit based on 5 L mini flotation cells. It is concluded that collectorless Cu/Pb flotation is a reliable phenomenon for this ore over the usual range of plant operating conditions.IntroductionFlotation of some sulphide minerals without the use of conventional collectors (e.g. xanthates) is now widely recognized. The requirement appears to be some degree of oxidation, although the nature of the surface product formed is still uncertain (Luttrell and Yoon, 1984; Buckley and Walker, 1988). The phenomenon has been termed ""collectorless"" or ""self-induced"" flotation. One of the minerals most responsive to coUectorless flotation is chalcopyrite; in contrast pyrite and sphalerite show little response and galena usually shows intermediate response (Hayes et al., 1987; Shannon and Trahar, 1986).Most of the work on collector1ess l1otation has involved single mineral or batch flotation on ore samples. There are only occasional references to collector1ess l1otation under plant conditions (Sandstrom and Jonsson, 1988; Vargas, 1990; Boyce et al., 1970). Creating and maintaining the appropriate oxidation conditions and differences in water quality are among the reasons why the phenomenon may not transfer readily to the plant (Grano et al., 1990). Periodically from the spring of 1989, Mattabi Mines Ltd. ran full-scale tests of collector1ess bulk CulPb flotation while treating Lyon Lake ore*: the observations confirmed the laboratory finding that chalcopyrite and galena floated without collector (Leroux et al., 1989).To explore this finding continuous in-plant testing using mini flotation cells was conducted which is the subject of this paper. The main objective was to determine if collectorless flotation was a reliable phenomenon over the expected range of redox conditions in the feed pulp to bulk CulPb roughing. As background, the previous work (Leroux et al., 1989; Martin, 1988) is briefly reviewed."

Jan 1, 1994

By Erica J. Wanless, Ghislain Bournival, Seher Ata, Jose Hamilton Tavares

In froth flotation valuable particles are captured by bubbles and transferred to a froth layer where bubbles are in close proximity. Bubble coalescence frequently occurs in flotation, especially in the froth layer. The coalescence of two bubbles causes a release of energy, which may expel particles from the bubble surface. A series of experiments were carried out to determine the effect of bubble interfacial properties on the detachment of particles upon the coalescence of capillary-held bubbles of 2 mm in size. The interfacial properties of the bubbles were changed by the addition of low molecular weight alcohols, namely 1-pentanol or methyl isobutyl carbinol (MIBC). Using esterified glass particles (? = 43 °) with a 10 % and 90 % cumulative passing diameter of 47.2 and 92.5 µm, respectively, as model particles, it was found a certain concentration of frother, different for each additive, is needed in order to observe a reduction in the detachment of particles. In the presence of frother, the detachment was evaluated at approximately 65 % which was a considerable reduction in the detachment compared with the value of approximately 85 % found in the absence of frother. Frother molecules changed the properties of the airwater interface. Upon the coalescence of two bubbles, the release of energy caused the merged bubble to oscillate; effectively resulting in the detachment of particles. The addition of frothing agents augmented the elasticity of the bubbles, which appeared to be related to the detachment of particles. Whereas frothing agents are generally used to prevent bubble coalescence and stabilise the froth phase, only transient stability is imparted. The results suggested that an additional role of frothers in flotation is to decrease the detachment of particles from bubble surfaces. The type and concentration of frother can be strategically selected to improve metallurgical recovery as an economic incentive.

Jan 1, 2016

By Jaroslaw W. Drelich

Despite the success of DLVO and extended-DLVO models that have been developed for homogeneous and smooth surfaces, a vast majority of practical surfaces encountered in mineral ore beneficiation are typically rough at various scales; they are also typically heterogeneous. The interactions of gas bubbles with particles having rough and heterogeneous surfaces are much more complex than the commonly used DLVO or extended-DLVO models predict. The effects of surface roughness on flotation and colloidal interactions have been reported many times in the past, although a clear understanding of their origins has been lacking. To explain differences in colloidal interactions for spherical hydrophobic particles, a theoretical analysis of the interaction potential was carried out for a model rough particle interacting with a bubble surface in an electrolyte solution in this study. The attractive hydrophobic interaction potential was added to repulsive retarded van der Waals and repulsive electrical double layer interaction potentials. The rough microscopic particles were modeled as spheres decorated with nano-sized asperities. Parameters that reflect common flotation separation systems were selected for testing this theoretical model and computation of the energy barrier applicable to particle – flat bubble surface interactions. It was found that hydrophobic asperities with the height of only several nanometers can reduce the repulsive interaction energy by an order of magnitude. Theoretical analysis also reveals that surface coverage of microscopic particles by nano-sized asperities is important as well. The findings of this research suggest that manipulating and engineering the particle surface topography could lead to better control over flotation separation.

Jan 1, 2016

By James F. Archibald

Testing has been accomplished to substantiate recent laboratory trials which have demonstrated that thin liner membranes, applied to rock core samples, can significantly enhance the structural performance of such rock materials. A range of Canadian polymer liner materials (MineguardTM, RockguardTM and RockWebTM) have been tested side-by-side to evaluate strength and other physical property improvements generated for two highly homogeneous, though differently sourced, granodioritic rock materials. Tests were conducted on physically similar core materials, utilizing 104 to 113 samples of each respective rock type. For both rock sample populations, cores were coated using linings at thicknesses varying between 1 and 7.3 mm, typical of the application range currently used underground by mines contemplating use of such membrane agents. Results of rock failure tests, following application of passive lining covers upon the very large sample populations of each rock type, have indicated that noticeable strength improvement and enhancement of post-yield failure characteristics can be developed by the entire range of spray-on liner materials evaluated. It is shown that all of the tested liner agent materials currently available can and do act to positively reinforce rock support capabilities of modeled core pillars. Where liner materials can be effectively placed underground, it is anticipated that they may provide similar benefit and be successfully used in partial replacement for either screen or shotcrete to provide advantageous area support for rock.

May 1, 2001

By José Cáceres

Mine To Mill? ? Carlisle(1954) ?The economic of a fund resource with particular reference to mining?. ? Steine(1978) ?Coarser grind may mean lower metal recovery but higher profit?. ? Metalica (1999) ?Mine Plant Integrated Planning?. ? JK (2002) Mine to Mill Strategic Planning ? Camus, Kelebek (2002) ?Management of Mineral Resources: Creating Value in the Mining Business?. ? Caceres (2003) ?Integrating Milling Parameters in the Mining Planning?

May 1, 2006

By J. F. Perreault, J. Paraszczak

"The profitability of an underground mine depends to a great extent on the production cost.Random equipment failures and their consequences have significant influence on the total operating cost of a mining system. Having this in mind, a reliability study has been initiated for loadhaul- dump machines in an underground mine. The main purpose of this study is to identify the critical machine subsystems, determine their failure pattern and help work out an effective maintenance strategy. In the first part of this study, the failure data of diesel powered LHDs, gathered during an I8-month period have been analyzed. For the purpose of the analysis, the machines have been treated as systems comprising seven subsystems connected in series. The most critical subsystems, i.e. electrical and hydraulic, were further investigated, and analyzed by graphical and analytical methods. Different failure distribution models were applied and discussed. Basic Defmitions and ConceptsIn order to avoid confusion, several terms used in this paper are defined below, as compiled by O'Connor (1991). The acronymsBS and MIL-STD stand respectively for: British Standard and US Military Standard.Failure: the termination of the ability of an item to perform a required function (after BS 4778).Time Between Failures (TBF): the length of time between two consecutive failures.Observed Mean Time Between Failures (MTBF): For a stated period in the life of an item, the mean value of the length of time between consecutive failures computed as a ratio of the cumulative observed time to the number of failures under stated conditions (after BS 4778).Maintenance, Corrective: The actions performed, as a result of failure, to restore an item to a specified condition (after MIL-STD-721 B).Maintenance, Preventive: The actions performed in attempt to retain an item in a specified condition by providing systematic inspection, detection and prevention of incipient failure (after MIL-STD-721B)."

Jan 1, 1994

By J. Mizera, B. Adamczyk-Cieslak, K. J. Kurzydlowski, A. Dobkowska

"AZ31 is the one of the most popular magnesium alloy using in the modern industry. It is well known, that compared with steel, magnesium alloys posse better properties, such as light mass, high specific strength or thermal conductivity. It should be noted that their application is limited by poor corrosion resistance. In this work the corrosion behavior of AZ31 magnesium alloy as cast and after heat treatment were described with the use of testing in neutral salt spray atmosphere.To characterise corrosion resistance and describe layers built on the surface it was necessary to do the metallographic observations with the use of optical microscopy. After that influence of heat treatment for AZ31 corrosion resistance was examined. Measurements were conducted by electrochemical impedance spectroscopy (EIS) and by neutral salt spray tests in artificial atmosphere. Surface and cross section morphology after removal of corrosion products were observed with the use of scanning electron microscopy (SEM).The weight loss measurements show that there is no significant difference between alloys as cast and with following heat treatment.INTRODUCTIONMagnesium and magnesium alloys are popular in modern industry because of the low density and good formability. Magnesium alloys are described by few properties which have got significant influence for their application in transportation and electronics industries (Feliu & Liorente, 2015). Their wide application is limited by poor corrosion resistance. As it is well known Mg is one of the chemically most active metal. Corrosion resistance of Mg alloys depends on several factors, such as impurities, chemical composition or working conditions (Cheng, Qin, Wang, & Zhang, 2009). That all causes that there are many different ways to find well defined and good solution of magnesium alloys processing to improve their corrosion resistance.There are many different versions about the influence of aluminum on the corrosion resistance of magnesium alloy. It is known that intermetallic compounds such as Mg17Al12 due to ß-phase content plays the minor role for corrosion resistance. It is proved ß-phase acts as cathode and it has good ability to build passive layer in broad pH ranges. However it should be noted that mentioned behavior depend on size and distributions of ß-phase in the microstructure (Singh, Singh, & Das, 2015)."

Jan 1, 2016

By B. Tougas

Recycling of titanium represents an important economic activity due to high cost of the material and the amount of returns of machined parts which represent the bulk of finished titanium products (typical "buy to fly" of 10 in the aeronautic industry). In the present work, the metallurgical quality of 76 mm in diameter and 20 cm ingots poured in coated graphite mold will be assessed against the nature and condition of application of 4 coatings namely aluminum oxide, yttrium oxide, zirconium oxide and zirconium oxide with 4% aluminum oxide. The metallurgical quality has been evaluated in terms of alpha case thickness, microstructure and composition. Microhardness from surface will be assessed against casting conditions. Least square regression analysis have been use to optimize casting conditions.

Jan 1, 2011

By Robert T. McKnight

"Traditional techniques for valuing resource projects companies have been primarily based on discounted cashflow methods (DCF) or by comparison to similar projects with an apparent market capitalization. Many resource projects are really forms of options to invest rather than a future cashflow stream. Employing the DCF method to value a resource project which is really an option to invest, can dramatically underestimate the real value of the project. The analytical tools required to evaluate options, while more complicated than the usual spreadsheets used for DCF, are becoming more easily available and usable by managers. This paper will discuss the background of options valuation and some of the tools which will make it easier for managers to estimate the value of projects and companies which have significant real option values.ResumeBob McKnight is a graduate of the University of British Columbia in Geological Engineering, supplemented by an MBA from Simon Fraser University. Following several years in the oil patch with Cities Service and Brascan, Bob returned to Vancouver in 1979 to work for Wright Engineers. He subsequently went on to work for Cassiar Mining, Getty Resources and Endeavour Financial before joining Pincock Allen & Holt Ltd. in 1998. His experience ranges from exploration to feasibility studies, financial evaluations of mining and oil & gas projects, due diligence, project finance, valuations and mergers and acquisitions. He has extensive international mining experience pertaining to such countries as Chile, Mexico, Uruguay, Thailand, Indonesia, Angola, Papua New Guinea, Kazakhstan.What are Options?Options have been around for centuries. They were familiar to Roman and Phoenician traders who were shipping cargoes from Mediterranean seaports. In the financial world, options are types of contracts that generally include the right, but not the obligation, to buy or sell a share, currency or commodity. The underlying commodity price or share price changes are assumed to be lognormally distributed. In this context, options are of two general types, ""call"" options and ""put"" options. Call options have the characteristic of having the right to buy a tradable commodity or currency at a predetermined price for a specified period of time. For the owner of call options, they become more valuable as the price of the underlying commodity increases. For the seller of call options, these options become an increasing liability as commodity prices rise, since there is the obligation to sell the commodity at a predetermined (perhaps lower-than-market) price. This characteristic of call options recently became high profile with the sharp rise in gold prices last year. The value of gold call options sold by certain producers increased their associated liabilities to the point where margin calls were made."

Jan 1, 2003

By George Carico

Research and related demonstration projects are being conducted in West Virginia on both existing and former coal surface mine lands to determine potential post-mine land re-use options that offer the greatest likelihood of future benefit and success. Examples of projects include renewable energy considerations that incorporate solar, wind, and/or biomass options, and contain components designed to educate business, government entities and the local community on renewable energy options and potential opportunities Multiple property re-use options are being researched and evaluated, based on site-specific conditions and characteristics, including infrastructure, local community needs and regional economic conditions. Re-use options being explored include innovative uses and needs, such as specialty housing, unique business and industrial needs, and an extensive variety of recreational and small business opportunities that best fit the specific needs of the local community and regional economic structure.

Aug 1, 2013

By M. S. Moats

"The effects of commercial copper electrorefining additives (glue and thiourea) on the electrochemical removal of bismuth are of importance in copper production. It was found that Bi(III) electrodeposition occurs readily from acidic sulfate solution via a diffusion-controlled quasi-reversible reduction. The diffusion coefficient of Bi(III) was measured and found to be less than reported values of copper in similar solutions. The presence of thiourea and/or glue was found to accelerate or de-polarize Bi(III) reduction on stainless steel as compared to the inhibition or polarization of Cu(II) reduction. The additives also inhibited the dissolution of the Bi-Cu co-deposit during cyclic voltammetry. During short term deposition studies, the additives increased the concentration of Bi in co-deposited Cu-Bi products from solutions with low concentrations of Cu (<2 g/L). Bi deposition was significantly suppressed by increasing the Cu(II) concentration in the solution. The formation of a copper layer on the stainless steel electrode appeared to significantly suppress the reduction of Bi(III). This study demonstrates that glue and thiourea depolarize the deposition of bismuth on stainless steel. Therefore, the additives could be used to improve Bi impurity removal during third stage liberation.INTRODUCTIONThe production of high purity copper has been steadily increasing due to the wide application of the metal and its alloys in electrical and electronic products, infrastructure construction, industrial machinery and equipment, general products and transportation (Moskalyk et al., 2003). Most high purity copper is manufactured from copper sulfide mineral concentrates and/or scrap via a pyrometallurgical process followed by electrorefining (Navarro et al., 1999). During the electrorefining process, cast anodes of 99-99.5% purity are electrochemically dissolved into an acidified copper sulfate solution while high purity copper (>99.99%) is plated on stainless steel blanks or copper starter sheets (Davenport et al., 2002). The control of cathode deposit growth (purity and morphology) while maintaining a high current efficiency is of significant importance for copper refining (Ilkhchi et al., 2007). At typically applied current densities for industrial copper electrorefining, mass and charge transfer play important roles in the quality of cathodic products (Hiskey et al., 1998). If the real current density at some surface points is substantially higher owing to uneven current distribution, then rough spots can and will grow faster leading to nodules (Suarez et al., 1992). Nodulated deposits tend to capture solution and anode impurities (slimes) resulting in unacceptable cathode quality (Afifi et al., 1987). Furthermore, these nodules can grow until they eventually contact the anode leading to short circuits and current efficiency reduction (Ilkhchi et al. 2007)."

Jan 1, 2016

By J. Koponen, M. van de Vijfeijken, L. Bos

"The availability and reliability of large grinding mills and their Gearless Mill Drives (GMDs) are of paramount importance for the grinding process. Although GMDs have been in service for decades, and are known for their operational efficiency (reliability and robustness with reduced operating cost per ton), compared to conventional drives, in the last decade due to certain reasons some failures led to serious unscheduled shutdowns and significant insurance events.The majority of these notable ""insured"" failures have happened on GMDs installed on relatively large mills, as the financial impact of a failure is proportional to the through-put of the mill. Despite the occurrences of these events, as mining operations are driven by lower ore grades and the ability to continue reducing operating costs per ton, the trend for having larger mills is still very present and there is no reason why this trend should not continue.It is obvious that if not handled correctly, the possibility of large value GMD loss events, coupled with the continuing increase in mill size or required availability and reliability targets, could potentially lead to major conflicts as it becomes difficult for the insurance companies to judge the risk and hence may result in hesitation to insure these grinding circuits. This paper will not only describe the conflicting situation from both an insurer&apos;s perspective and from an equipment supplier&apos;s perspective, but also how these conflicting challenges can be successfully mastered. It has to be noted that not only the mining companies themselves, but also their insurance companies and the involved equipment suppliers have a common interest: to reach the highest availability and reliability in order to avoid or at least minimize unscheduled shut down times, and most importantly prevent unplanned events that result in extended production stoppages or reductions in through-put of GMD driven mills.From the very beginning onwards, the complete service concept together with emergency plans must be integrated on every level in the design of the grinding circuit. This approach must be implemented continuously and without compromises by all involved parties during all following stages, such as basic design, detail design, manufacturing, quality inspection and testing, packing, transportation, storage, installation, commissioning, operation and maintenance. The concept of formal risk analysis related to mill operations, maintenance and spare parts strategies must be an integral part of mining companies’ decisions related to the selection for installation and continued use of large mills powered by GMDs. The service concept in place for operating mills shall also have a clear focus on very early detection of any abnormalities, so that the risk can be mitigated and unscheduled shutdown times avoided. However, if a major failure occurs, then procedures and tools shall already be available in order to ensure that production impact is minimized."

Jan 1, 2012

By A. M. Cormie

Introduction The purpose of this paper is to give a brief, general outline of mining practices at Torbrit Silver mine. The geology of the mine is touched on as it is felt that a rough picture of the geology will result in a clearer understanding of the mining methods employed. The main part of the paper deals with mining methods and a section is included on haulage. Development practice is mentioned only briefly. Torbrit Silver Mines, Limited, a subsidiary of Mining Corporation of Canada, is located in the Alice Arm area of northern British Columbia. Access to the mine is by boat to the village of Alice Arm at the head of Alice arm, then truck road, following the course of Kitsault river for 18 miles in a northerly direction to the plant site. The main portal is a further two-thirds of a mile along the course of the river, at approximately the same elevation as the plant, 1,014 feet above sea level. Geology The ore occurs in a massive, irregular-shaped quartz-barite body replacing a folded area in a series of volcanic breccias, tuffs, and flow rocks locally referred to as &apos;green-stones&apos;. A series of parallel, nearly vertical, fine-grained basic dykes cut across the formation at right angles to the strike of the ore belt over a horizontal distance of 140 feet. The whole of the quartz-barite vein material, which ranges up to several hundred feet wide in places, carries silver values but commercial grade is confined to lenses and shoots where there have been more than usual concentrations of native silver and silver-bearing minerals. The ore-bearing structure plunges at approximately 25 degrees along an axis striking roughly N.65°W.

Jan 1, 1951

By K. Wood, L. Duval

"The paper discusses the approach used to add a new, separate 5000 t/d copper-zinc treatment circuit to an existing, 1650 t/d copper circuit, essentially within the existing mill building. Temporary installation of new equipment allowed renovation and expansion within existing operating areas. Production in the original circuit was maintained at rated capacity throuqh0ut the construction period through close co-ordination between operating and construction groups. Downtime for circuit and service tie-ins was minimal. Both circuits are described briefly.For presentation at Canadian Mineral Processors Conference Ottawa, January, 1987.INTRODUCTIONLes Mines Selbaie is located in the Abitibi region of northwestern Quebec, in what has recently become better known as the Casa-Berardi-Joutel area. Les Mines Selbaie is operated as a joint venture project managed by Selca Division of BP Canada Inc. and owned 55% by BP Canada, 35% by Esso Minerals Canada and 10% by Trans Canada Pipelines."

Jan 1, 1987

By B. Dubreuil, J. -M. Lalancette, D. Lemieux

Arsenical bearing deposits are posing an increasing challenge for the mining industry. In particular, mineral processing of arsenical sulfidic ores for base and precious metals recovery tend to produce problematic arsenical tailings. This arsenic being present as sulphide or oxide, tends to dissolve, contaminating surface and underground waters. To meet the environmental regulations, it is often required to stabilize the arsenic in a more insoluble form. Dundee Sustainable Technologies has developed a new patented technology using vitrification of the arsenic oxide in an economical way, giving a stable solid, well below the environmental regulations upon leaching. This technology involves oxidation of As (III) to As (V), by using a low cost natural oxidizer and transformation of the produced arsenic oxide into calcium arsenate, which is not volatile at the melting temperature of the glass. This technology would be advantageously applied on most cases around the world where sulphide concentrates are oxidized in a fluidized bed or smelted.

Jan 1, 2014

By L. Fernandes

A two level factorial study was undertaken to investigate the relative impacts of factors affecting the kinetics of polytetrafluoroethylene, PTFE, assisted pressure oxidation of chalcopyrite. A copper flotation concentrate, principally composed of chalcopyrite, was leached in 850 mL of leach solution under conditions similar to those of the CESL process. The factors manipulated were: the amount of 1/8" PTFE beads added (100 g or 650 g), oxygen pressure (690 kPa or 1030 kPa), and concentrate addition (10 grams or 65 grams). Copper extraction data, which indicated complete leaching under certain conditions, were fit using a shrinking core model from which rate constants were estimated and further used to generate a statistical model containing only the factors of significance and their interactions. Results indicated a strong positive effect of PTFE addition and a strong negative effect of increasing pulp density. A weak negative interaction between increasing PTFE addition and pulp density was attributed to PTFE/concentrate agglomeration.

Jan 1, 2014

By G. Tairova, J. Ioffe

Arsenic, selenium and mercury species are common contaminants in mining aqueous streams and present significant environmental and health problems. The objective of this project is to investigate methods to lower the concentrations of these elements in mining aqueous streams. A new composite media for removal of these elements of concern from mining effluents was developed. The results of bench scale and pilot plant experiments, using the media, indicated removal of arsenic, selenium, mercury and other elements of concern below detection limits.

Jan 1, 2014

By Ken Woloschuk

??Owners?Perspective ??Owners?Challenges ??EcoNomics?Delivery Model ??Projects ??Project Outcomes ??Questions ??Balancing the triple bottom line initiative: ?shareholders expectations of economic costs and benefit; ?stakeholders expectations of social and environmental costs and benefits; ?deciding what is sustainable and which design alternatives are the most sustainable. ?? Delivering required project outcomes

May 1, 2008

By J. E. Lee

"This paper describes the current practices and experiences, and discusses design parameters concerning slurry pumping at Inco Metals Company in the Sudbury District. It deals mainly with the long tailing and concentrate lines. Subject matter is arranged under the following headings: pumps, lines, instrumentation, system design, operation.IntroductionThe Inco Metals Company is the mining and processing section of INCO LIMITED. In the Ontario Division, it operates 13 mines, 5 mills, a smelter, an iron ore plant and 3 refineries, all engaged in the mining and recovery of nickel and copper. This paper describes the slurry pumping practices in the mills of the Ontario Division.The PumpsWe have in our Sudbury area mills most of the available types of slurry pumps, in sizes from one inch up to twelve inches, a total of about 400 pumps. The rubber-lined, horizontal shaft pump is; most numerous. However, for certain applications, the hard-metal pump is essential, and is becoming more popular for general mill service. Two types of vertical shaft pumps are used. There are a few diaphragm pumps on small thickeners, but the larger thickeners have centrifugal pumps either directly connected to the under-flow or with one pump handling several gravity underflows. We have not used piston or plunger pumps in our mills."

Jan 1, 1978

By T. McCallum, B. Wellbrook, T. Ratnaweera

Leaching of copper (Cu) concentrates produces elevated concentrations of Cu and acid, which makes solvent extraction (SX) processing more challenging. Maintaining extraction targets can be more difficult with higher pregnant leach solution (PLS) grades, and variability of PLS Cu and acid can lead to increased chemical iron transfer. Diluting concentrate leach feeds with an existing heap leach inventory makes SX processing easier. However, considerations about how much to dilute and where to distribute the flow into the SX configuration must be carefully evaluated, given their impact on metallurgical performance. In this paper, characteristics of a concentrate leach feed are discussed, along with considerations for processing by SX. Also reviewed are pilot plant results of concentrate leach distribution into SX and plans for commercial testing. INTRODUCTION Hydrometallurgical processing of copper concentrates continues to gain interest from the industry. Treatment by smelting and electrorefining continues to dominate, accounting for ~80% of global copper production, but is faced with its own challenges (Li et al, 2017). The case for increased hydrometallurgical processing has been discussed as high grade ore deposits are diminishing, capital costs for smelting are high, and the environmental aspects present challenges for sustainable practice. The hydromet copper industry is also turning a corner as easily leachable copper oxide deposits are depleting, and excess SX-EW capacity exists in certain regions. The transition to hydrometallurgical processing of copper concentrates will take a bit of effort as leaching of copper sulfides is difficult and byproduct credits must be considered. Various POX leaching processes have been studied and proposed to the industry as viable practices. Of the many processes, commercial use has been practiced with the Mount Gordon Copper Process, total and partial pressure oxidation by Freeport-McMoRan at their Bagdad and Morenci, Arizona complexes, the Sepon Copper Process in Laos, and the bioleach BIOCOP™ process in Chile (Dreisinger, 2016).

Jan 1, 2019